Inga edulis
Inga edulis, also known as joaquiniquil, cuaniquil, guama, guaba, or (in places where it constitutes the only inga tree) simply as inga, originated in South America. A leguminous tree, it can form symbiotic relationships with rhizobial bacteria and mychorriza to fix nitrogen in the soil. It also forms symbiotic relationships with ants to protect it from herbivores.
#Human relations
As climate change heated up more of the globe during and immediately after the collapse of civilization, humans spread the inga tree far beyond its native tropical bioregions. Its rapid growth, nitrogen-fixing properties, and resilience in the face of both flooding and drought made it a popular choice for restoring depleted soils.
In particular, it became the basis for a method of horticulture known as Inga alley cropping, an alternative to swidden cultivation. In this system, the inga trees are planted close together in rows, with an "alley" of about four meters between each row. After two years, the trees have grown and filled in the canopy. The gardeners then prune the trees, using the larger branches for firewood and leaving the smaller branches and leaves on the ground as mulch. In the mulch, the gardeners plant other crops (for instance, the Three Sisters). Gardeners continue to prune the inga trees, adding more mulch to protect the crops below and add a new top layer of soil over time.
In addition to its use in sustainable horticulture, of course, people use the inga tree for a variety of purposes. Indigenous peoples of the Amazon have long cultivated it for timber, shade, medicine, and its edible beans (the pulp of which tastes reminiscent of vanilla ice cream -- although the fluffy texture more closely resembles cotton candy). People eat the pulp raw, or ferment it into a traditional alcoholic beverage known as cachiri. The seeds contain toxic compounds, but one can neutralize those via cooking. Once cooked, the nutritious seeds taste reminiscent of chickpeas.
In traditional South American folk medicine, people use different parts of the tree to treat ailments as diverse as diarrhea, arthritis, rheumatism, coughing, and lip sores. The wood also makes excellent firewood, as it produces little smoke.
#Inga People
When a community focuses on its relationship with the inga tree to make a living, it can shape their lives in a wide variety of ways. A few examples include:
A community that specializes in relationship with the inga tree will invariably tend towards horticulture, and therefore live in settled villages at least part of the year. They will certainly practice Inga alley cropping rather than swidden cultivation. Due to inga's unique role in spreading tropical horticulture across the globe during the chaotic time of transition from the Fourth World to the Fifth, inga people may trace their descent from dedicated horticulturalists who evangelized the use of inga to restore depleted soils and establish new sustainable agroforestry in places devastated by civilization and climate change. They likely have a deep commitment to sustainable cultivation, and believe humans have a responsibility to use their intelligence to cultivate new, abundant ecosystems. However, gardening, while not necessarily unsustainable, can easily fall out of balance. Communities in the Fifth World who practice horticulture often have a number of ways in which they strictly control reproduction, including a variety of methods of birth control. These communities place special emphasis on monitoring the health of the forest and ensuring that it properly regenerates.
If the community's territory endured a great deal of ecological catastrophe during collapse, losing its previous ecosystem entirely, the community may mythologize the arrival of inga trees. They may have a goddess figure named Inga, who came to their ancestors in their time of need, bringing the land back to life and teaching them how to live in harmony with the Earth by joining with other forms of life (such as fungi and insects). They likely observe a yearly festival in her honor. Visual art may depict her as a tall woman with voluminous, dark hair (dark as the tree's leaves, thick as the canopy). The name "Inga" may become a popular given name -- or may stand as a rare name that one can only earn in adulthood or even elderhood by becoming a master gardener, teacher, or both.
Alternatively, an inga community may trace its descent from the original cultivators of the tree. They may continue to live within the tree's native range, or their ancestors may have fled climate change-caused flooding. Other inga communities, newer to cultivating the tree, may look to them as elders who can share their ancestors' wisdom on how to live sustainably in tropical environments. Their ancestors may themselves have become inga evangelists, spreading the tree widely and teaching people how to grow and relate to it responsibly. They may take their role as elders to the world very seriously, with master gardeners in their community continuing to teach pilgrims who come to them for guidance or going on trips to ensure the continued health of gardens worldwide.
The inga tree provides excellent shade to coffee, cocoa, and tea. It could therefore become the basis for a "dessert guild," perhaps also featuring vanilla and even sugarcane. A community that grows that guild more likely than not has a sweet tooth, and will become very popular with neighboring communities for their trade in luxury goods. They may become political power brokers, successfully negotiating for the generous use of local resources, because the other communities in the area don't want to lose their source of delicious sweets. They will also likely have many trading partners, perhaps producing a number of traders themselves. Trade will bring in more luxuries from farther afield, as well as news from all over the world, making such a community worldly and rich in exotic goods. However, while they may trade the other members of this guild, they cannot trade the inga bean itself, as it quickly goes bad. If few other communities in the area grow the inga tree, this may attract visitors to their territory.
Because Inga alley cropping allows gardeners to cultivate the same plot of land for many years, protecting one's territory becomes extremely important. This will likely result in the development of a scouting tradition, which helps them keep an eye out for any threats or encroachment on their land and warn away would-be attackers while avoiding out-and-out war.